Deacidification characteristics of <i>Issatchenkia terricola</i> WJL-G4 with a special focus on bioactive compounds and antioxidant activities during currant juice and wine processing

Abstract Issatchenkia terricola WJL-G4 (WJL-G4), known for its strong deacidification ability, was selected for processing currant juice (CJ) and wine to address the issue of excessive acidity. This research aimed to examine how acid-reducing fermentation (ARF) impact the quality of juices and wines in terms of bioactive compound content and antioxidant capacities. In CJ (black, red, white), citric acid degradation reached 80.55%, 79.60%, and 77.51% after 80, 84, and 88 hr of ARF, respectively. The results indicated a decrease in bioactive compounds in juices post-ARF, whilst the impact on wines was less pronounced. However, concentrations of isovitexin, epicatechin, sinapic acid, coumaric acid, syringic acid, and rutin were increased after ARF. Significantly, the antioxidant capacities of red currant wine with WJL G4 were markedly higher compared to red currant wine without WJL-G4. This study revealed that I. terricola WJL-G4 ARF reduced organic acid content whilst preserving bioactive compounds and enhancing wine colour.